Abstract

We report the measurements of conductivity, curve, and magnetoresistance of a single Au/polyaniline microfiber with a core-shell structure, on which a pair of platinum microleads was attached by focused ion beam. The Au/polyaniline microfiber shows a much higher conductivity ( at ) and a much weaker temperature dependence of resistance as compared with those of a single polyaniline microtube [ and ]. The power-law dependence of , with , indicates that the measured Au/polyaniline microfiber is lying in the critical regime of the metal-insulator transition. In addition, the microfiber shows a dependent positive magnetoresistance at 2, 4, and .

Received 26 July 2005Accepted 23 March 2006Published online 20 April 2006

Acknowledgments:

This project was financially supported by the National Natural Science Foundation of China (Grant Nos. 10374107 and 20475053). The authors also thank the National Center for Nanoscience and Technology of China for support.